Platen-adjusting device



April 15, 1930. ARRANZ 1,755,143

PLATEN ADJUSTING DEVICE Filed May 19. 1928 2 Sheets-Sheet 1 j iga. 1.

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INVENTOR'.

ATTORNEY- WITNESS:

April 15, 1930. 1.. ARRANZ ,755,143

PLATEN ADJUSTING DEVICE Filed May 19, 1928 2 Sheets-Sheet 2 Lazzzwzo fi m/70:.

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V I BY 5 ATTORNEY,

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' without necessitating any attention by the p Patented Apr. 15, 1930 I umrao e f-Arias sMENToFFicE; 1

LORENZO 'ARRA Iz, or NEW YORK; N. Y.

'rnArmv-Amusrme DEVICE Application filed May 19, 1928. Serial No. 279;1'04.

' This invention relates-to typewriterletter spacingdevices, and particularly to fractionalletter spacing mechanism.

On operation of the keys of atypewriter to 7 5 produce impressionson a worksheet carried f by the cylindrical platen, thetype bars are effective to'move a universal bar to cause the platen to be fed in 'letterspace direction anj equal distance for each impressionor char 1 10 acter'typed, and as the platen is also revo-. luble in line space direction an equal distance for each linewritten the-result is that-the type faces strike thesamepoint on each line onsecond and subsequent revolutions of the 18 platen, thereby causing indentations or holes to be made in the surfaceof the platen, which is usually of rubber, with; the result that blurring of the characters produced on the i work sheet is caused.

' 20 The primary object of this invention is the provision ofme'ansfor moving the platenat predetermined intervals, relatively to the type bars, so that the impressions'will be produced on "a different point of the platen "25. aftereach operation of said means, thereby causingclear impressionsflt'o bee-made and preventing the formation of holes in the material of the platen.

As the work sheet lsusu'allyheld in mov- 30 able-contact with thefsurface' of the platen" byco-operating feed rolls, which are releas able by a feed roll operating lever for inseri tion or removal of the work sheet, it is another object of my invention to utilize the K feed roll leverfor operating my fractional letter space device. It will therefore be 'seenj I that on insertion of each work sheet the platen isautomatically so moved that theim pressions are received on the sheet opposite a different point of the surface of the platen,

typist." .-i. I I I "With" these and other objects in view, the

invention resides in certain'novel' construe parts, the essential "features of which are hereinafter fully" described; are particularly pointed outin theappended cl'aimsiand are illustrated in; the accompanying drawing, i

tion and combination and arrangement of Figure 5 is an elevational view partly sectional on the line5'5 of Figure 1.

Figure 6 is a perspectiveview of the operating lever for the ratchet wheeland the parts o-f a pawl in a separaterelation; Referring particularly'to the drawing; the numeral 10 designates a cylindrical platen which, by hand wheels 11 rigidly'mountedon an axle 12 or byline space mechanism generally representedat 1-3 is revoluble for feeding, in co-operation; with front'and rear pressurje'rol'ls 14f, asheetof paper on which i the imprint-of the usual types? is" receiveda' The axle12 is journalled 'in end plates=15 o'f'the platen frame 16' which'is movable laterally in: letter feed and returndirection, while thepressure of thefeed' rolls'on-the work sheet may be applied and released'by a lever 17. So, far the mechanism described typewriter.

Revolubly mounted bya hub" 1-8 on the platen shaft 12, Iprovide a ratchet wheel'19 1 may be likefthat found in 7 any, wellknown; I

having a flange 20, the exterior periphery'of whichis formed with appropriate ratchet teeth 21, while threeradially disposed'pins 22 projecting from the inner vface of-- said flange carry rollers 23 for a purposeto pres c;

ently appear. V

Fixe'dly mounted von the right/hand plate-n 7 frame 15, as by a-bracket 24with screws25,

and havinga hub 26in which theshaft 12 is revolvable, there is'a'disk 27 the flange-2550f which is formed with threeequzillyprojct in'g' cam points 29 midway betweenqwhich are} recesses 80, thusforminga curved 'ciam rib', the face off which forms a track for said rollers23fl' "is V The feed roll release lever 17 is pivoted on the platen frame as at 31 and has in its lower terminal an aperture 32 to receive the stem of a screw 33 by which a pawl 34 is pivoted on said lever, the screw being secured in a tapped hole.35 in the angnlarly turned turned cars 44 between which a compression 53 to hold said ratchet wheel fast.

spring 45 is located on a detent pin 46 to strongly urge one end of the latter against,

a tooth of the ratchet wheel. The pawl 34 is supported as at 47, while the lever 17 nor mally rests against the rear of the platen frame represented at 48. To accommodate the invention, the platen is urged against a friction washer 49 by a spring 50, the shaft 12 being capable of limited sliding move ment through the plates 15.

It will readily be seen that, in practice, the ratchet wheel 19 is individually revolvable on operation of the lever 17, which, when advanced to the dot and dash position shown in Figure 5, draws the pawl 34 rearwardly, the detent 40 at the same time contacting with a tooth 51 to move a tooth 52 past the pin 46, the latter then resting against 26 tooth turn of the lever to its normal position the spring pressed detent 4O slides over a tooth 54 to rest against another tooth 55.

As there are a greater number of teeth on the ratchet wheel than on the usual line space wheel of the machine, it will be seen that the action of the lever 17 also rotates the wheel 19 a fractional part of a line space, and as there is an inclination from vertical of the face of the cam rib, it will be evident that there is a limited horizontal travel or fractional letter space movement of the platen, while the wheel 19 is rotated one tooth interval and while the rollers 23 move a corresponding distance over the cam face. This fractional longitudinal travel of the platen isto the right, urged by the spring 50, as a roller 23 moves from a projection 29 to a recess 30; and to the left, urged by the lever 17 acting through the wheel 19 against the The depth of the curve: of the cam face, measured horizontally fromvolve said wheel one tooth space, is one fifth of a' letter space. Normally said lever is operated, and therefore the platen automatically adjusted for wear distribution of its surface 7 between letter spaces, each time the feed rolls 14 are released to insert a work sheet. The longitudinal platen movements are, of course, to the right and to the left alternately, as the rollers descend and ascend the inclined surfaces of the cam while the rotary movement of thewheel 19, which carries the rol1- ers, is always in one direction, as indicated by'the arrow in Figure 5. r 7

While I have described what I deem to be the most desirable embodiment of my invention, it isobvious that many of the details may be'varied without in any way departing from the spirit ofmy invention, and I therefore do not limit myself to the exact details of construction herein set forth nor to anything less than the whole of my invention limited only by the appended claims.

W hat is claimed as new is z 1. A fractional letter spacing device for a typewriter comprising a platen and its shaft and a frame therefor, a disk rigidly mounted on said frame wherein the shaft of the platen and a revolvable ratchet wheel having rollers thereon for travelling along said cam rib to slide the platen and shaft limitedly. 2. A fractional letter spacing device for a typewriter comprising a revolvable platen and its shaft and a frame therefor, a disk rigidly mounted on said frame wherein the shaft of said platen is longitudinally movable, a lateral cam rib on said disk having a projection thereon, and a revolvable ratchet wheel carrying rollers for traveling past said projection to move the platen'longitudinally. 3. A fractional letter spacing device for a typewriter comprising a'longitudinally move ableplaten having a shaft and a platen frame wherein said shaft is revolvable, a fixed disk wherein said shaft is revolvable, a cam rib. on said disk having a recessed. face, a separately revolvable ratchet wheel on said shaft adjacent the disk, and rollers on said ratchet wheel adapted for movement over the recess of said cam face to move the platen longitudinally a predetermined distance upon turning of said ratchet wheel. 'f

4. A fractional letter spacing device for a typewriter comprising a revolvable platen and its shaft and a frame therefor in which the platen is longitudinally movable, a fixed disk on said frame wherein the shaft of said platen is 'revolvable, a curved cam -surface on said disk, a revolvable ratchet wheel having an annular flange, the cam face of said disk located internally of said flange, and aplurality of rollers carried by said flange internally thereof for traveling on said cam face to move the platen longitudinallyon turning. of said ratchet wheel.

5. A fractional letter spacing device for a typewriter comprising in combination a platen and its shaft and a frame therefor in which the platenis longitudinally movable, pressure rolls co-operating with the platen and-a release lever for said rolls, a disk rig idly mounted on said frame wherein the shaft of the platensis revolvable, a ratchet wheel having a flange and teeth peripherally thereof, rollers carried by said flange internally a thereof, said disk having a rising andfallingcam face onwhich said rollers are adapted to travel, to fractionally move the platen endwise between letter spaces, and a pawl connecting said lever with the teeth of said ratchet wheel to automatically rotate the latter on release of said feed rolls. 7

' 6. A fractional letter spacing device for a typewriter comprising in combination a platen and its shaftiand a frame therefor in which the platen is longitudinally movable, pressure rolls co-operating with the platen, I a release lever .for said rolls, adisk rigidly V mounted on said frame wherein the shaft of the-platen is revolvable, a ratchet wheel having a flange and teeth peripherally thereof, rollers carried by said flange internally-thereof, said disk having arising and falling cam face on which said rollers are adapted to travel tofractionally movetheplaten end wise between letter spaces, a pawl automatically operated by said lever on release of said feed rolls, and a compression spring on the shaft of the platen to urge the latter endwise to maintain connection between said rollers and said cam face. 7

7, A fractional letter spacing device for a typewriter comprising a platen frame, a shaft having a platen fixed thereto and 1on gitudinally slidable in said frame, a cam element'fixed to said frame through which the shaft is slidable, and ,a separately revolvable device onsaid shaft cooperating with said cam element to slide the platen and its a shaft longitudinally. v r

Y 8. A'fractional letter spacing device for typewriters comprising a machine having a 1 platen frame, a shaft having a'platen fixed thereto and longitudinally slidable in said gitudinally slidable shaft and a platen fixed thereto, afixed cam member having an undulating surface, spring means for sliding the platen with its shaft in onedirection,

manuallyoperable means for sliding said platen with its shaft in the opposite direc-.

tion, saidlatter means comprising a rotatable wheel turnable on said shaft with respect to the platen, and rollers carried by said wheel for riding over said undulating cam surface. 10. In a typewriting machine having a longitudinally slidable shaft and a platen fixed thereto, a fixed cam member having'an undulating surface,'spring means for sliding,

the platen with'its shaft in one direction,

said latter means comprising a ratchetwheel' revolvablymounted on said shaft, rollers carried by said wheel for-riding over said undulating cam surface, and manipulating pawl mechanism correlated with said ratchet wheel for imparting predetermined turning movement thereto in onedirection.

In testimony whereof I have afiixed my' signature.

LORENZO ARRANZ.

I frame, a cam element'fixed to saidframe and having, an undulating surface, andamem- 1 v her 'on said shaft, between said platen and l 65 said cam element, provided with rollers, said its a 

